I noticed this games from COMPILE are not listed in SHMUP.COM....this no more tolerated!!!!
We are talking about one of the best shooter of all times!
There're 3 games of this series:
POWER STRIKE 1 (SEGA MASTER SYSTEM)
POWER STRIKE 2 (SEGA MASTER SYSTEM)
POWER STRIKE 1 (SEGA GAME GEAR)
POWER STRIKE 2 (SEGA GAME GEAR)

it seems that the Game Gear version is the best but I never played it because I don't have a GG And I don't like handheld emulation...

Aleste GG I & II are pretty expensive and hard to find. They are must have in spite of their price. (about 9.000 yens ).
Power Strike is the name of Aleste serie out of Japan.
Power Strike GG (I & II) and Aleste GG (I & II) are the same.